2.67 Repeating as a Fraction- Complete Calculation Guide
What Does 2.67 Repeating Actually Mean?
2.67 repeating is the decimal number 2.676767... โ the "67" goes on forever. It's not 2.67 rounded. It's not approximately 2.67. It is exactly 2.6767676767... and keeps going.
Mathematicians write this as 2.67 with a bar over the 67, or sometimes with parentheses: 2.67 or 2.(67).
Here's the thing: repeating decimals are rational numbers. They can all be written as fractions. 2.67 repeating is no exception.
The Fraction Conversion: Step by Step
Let's convert 2.676767... to a fraction.
Step 1: Set Up the Equation
Let x equal the repeating decimal:
x = 2.676767...
Step 2: Multiply to Match the Repetition
The repeating part is "67" โ that's 2 digits. Multiply both sides by 100 (which is 10ยฒ):
100x = 267.676767...
Step 3: Subtract to Eliminate the Decimal
Subtract the original equation from this new one:
100x - x = 267.676767... - 2.676767...
99x = 265
Step 4: Solve for x
x = 265/99
That's the answer. 2.67 repeating as a fraction is 265/99.
Can You Simplify 265/99?
Let's check. Find the prime factors:
- 265 = 5 ร 53
- 99 = 9 ร 11 = 3ยฒ ร 11
No common factors. 265/99 is already in lowest terms.
As a mixed number: 2 67/99
How to Verify Your Answer
Divide 265 by 99 to check:
265 รท 99 = 2.676767... โ
The decimal repeats "67" exactly. Your fraction is correct.
Why This Method Works
You're using algebra to cancel out the infinite decimal. Here's the logic:
- You have x = 0.ABABAB... where "AB" is the repeating part
- Multiply by 100 shifts the decimal two places
- Subtracting removes the decimal portion entirely
- You're left with a simple equation to solve
The same process works for any repeating decimal, regardless of how many digits repeat.
The General Formula for Repeating Decimals
For a repeating decimal with a single-digit repeat (like 0.3ฬ):
x = 0.333...
10x = 3.333...
10x - x = 3
x = 3/9 = 1/3
For two-digit repeats, multiply by 100. For three-digit repeats, multiply by 1000. The multiplier is always 10^(number of repeating digits).
Quick Reference Table
| Repeating Decimal | Fraction | Mixed Number |
|---|---|---|
| 0.3ฬ | 1/3 | โ |
| 0.1ฬ6 | 1/6 | โ |
| 0.14285ฬ | 1/7 | โ |
| 0.9ฬ | 1/1 | 1 |
| 1.2ฬ3 | 122/99 | 1 23/99 |
| 2.6ฬ7 | 265/99 | 2 67/99 |
| 3.1ฬ4 | 313/99 | 3 16/99 |
Common Mistakes to Avoid
- Confusing 2.67 with 2.67 repeating. 2.67 = 267/100. 2.6767... = 265/99. Different numbers.
- Using the wrong multiplier. If the repeat is "67", use 100. If it's "7", use 10.
- Forgetting to subtract. The subtraction step is what removes the decimal. Skip it and you're stuck.
- Not simplifying. Always check if your fraction can be reduced further.
How to Get Started: Converting Any Repeating Decimal
Here's the process you can apply to any repeating decimal:
- Identify the repeating block and count its digits (let's call this n)
- Multiply the decimal by 10โฟ
- Subtract the original number from the result
- Divide both sides by (10โฟ - 1)
- Simplify if possible
Example: 0.1ฬ6
- Repeating digit is "6" โ n = 1
- x = 0.1666...
- 10x = 1.666...
- 10x - x = 1.6
- 9x = 1.6 = 16/10
- x = 16/90 = 8/45
That checks out. 8/45 = 0.1777... wait โ let me recalculate. Actually 0.1ฬ6 = 0.1666... = 1/6 = 15/90 + 1/90... The fraction is 1/6.
The Bottom Line
2.67 repeating as a fraction is 265/99. That's it. No tricks, no rounding, no approximation.
The conversion method works every time: multiply, subtract, divide. The math is reliable. Use it whenever you need to turn a repeating decimal into its exact fractional form.